comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Re: subscripting arrays with dim > 1

Re: subscripting arrays with dim > 1
type: item
description: Gwyn: I would take the following approach: IDL> index1 = 0 IDL> index2 = 4 IDL> print,array[index1,index2] That doesn't seem very elegant, until you start making arrays. For example, IDL> print,array[0,4],array[3,3] 20 18 IDL> index1=[0,3] IDL> index2=[4,3] IDL> print,array[index1,index2] 20 18 You can even make index1 and index2 multidimensional arrays, so long as they have the same dimensions. Your result should have the same dimensionality as your index arrays. Bill Thompson fireman@aerialist.gsfc.nasa.gov (Gwyn Fireman) writes: > I'd like to reference an array with a variable containing a subscript for > each dimension, passing the subscripts as an array. For instance: > IDL> array = indgen(5,5) > IDL> print,array > 0 1 2 3 4 > 5 6 7 8 9 > 10 11 12 13 14 > 15 16 17 18 19 > 20 21 22 23 24 > IDL> print,array[0,4] > 20 > But I can't seem to reference each dimension. Instead, the subscript array > is passed as two instances of a single subscript: > IDL> index=[0,4] > IDL> print,array[index] > 0 4 > I can of course calculate a single index, but it seems a bit clunky: > IDL> s=size(array) > IDL> print,s > 2 5 5 2 25 > IDL> print,array[index(0)*s(1)+index(1)*s(2)] > 20 > - or - > IDL> print,array[long(total(s(1:s(0))*index))] > 20 > Is there a better way? > Gwyn > -- > __. > / | , , , , , ,_ Gwyn F. Fireman > (__/|/(_(_)(_/|/| |_/ General Sciences Corporation > /| /| Gwyn.Fireman@gsfc.nasa.gov MODIS Characterization Supp. Team > (_/ (_/ 301-352-2118
creator: thompson
date: 1998-08-28T07:00:00-00:00